1. Field of the Invention
The system of the present invention relates to fuel tanks. More particularly, the present invention relates to a system for cleaning a fuel tank of a vessel such as a boat, or for cleaning an underground storage tank, construction equipment, or other types of vehicles. It may also be used in conjunction with maintaining the fuel in a vessel clean by placement intermediate the fuel tank and the engine of the vessel.
2. General Background
One of the more difficult problems in the burning of liquid fuel such as diesel fuel or gasoline in large quantities such as on board vessels ships, boats, or for use in other settings such as gas diesel driven generators, is the accumulation of debris over a given period of time within the tank, and the presence of that debris in the fuel that is being utilized by the engine in that system. Of course, this debris or other type of contamination is detrimental to the overall operation and continued life of the engine, and creates difficulty in maintaining the smooth running of the engine during the use of it.
In an effort to rectify this problem, systems for cleaning fuel tanks have included the removal of water and sludge from the fuel through the use of various means. For example, a concentric suction--discharge arrangement has been used in drilling operations for many years; likewise gravity separators and cartridge filters are used in many different applications in the industries. However, the use of a cartridge filters as a direct filter means of cleaning of diesel is a very expensive proposition, in view of the fact that the major sludge found in diesel or the like fuel begins to clog up a cartridge filter very quickly, and therefore the filter must be changed quite often. This of course leads to much expense in the operation.
In U.S. Pat. No. 3,362,534 entitled "Fuel Water Separation Method And Apparatus", issued to Guenterl. Kay, presents a system which is part of a fuel supply system included with a diesel engine power plant which systematicaly and continuously should remove contaminants to assure a clean fuel supply to the engine. The U.S. Pat. No. 3,362,534 relates to the separator within the system, with the separator and the filter operating on a vacuum. In the system under the U.S. Pat. No. 3,362,534, there is no agitation of the fuel in the tank; consequently the bottom of the tank below the suction is not agitated at all, except when the fuel level is very low, and in such an event many fuel cleaning systems included in engine installations, do, in fact, become plugged when dealing with unusually high level of contaminants.
There is known in the art a system utilized by Papworth Industries also for cleaning fuel in a tank. The Papworth system operates on a vacuum. The pumping unit and filter is a self-contained unit which is located remotely from where the suction/discharge similarly enters the tank. The Papworth system cleans the fuel with a self-contained single filtering unit in which the first step is for the fuel to pass over foam pre-filter. Thus, 100% of the fuel and contaminants pass over the foam pre-filter and at some point the unit must be shut down to remove the contaminants. In the Papworth unit the second stage is a coalescent shroud which is designed to move water. The final filtration step in the Papworth unit is through a stainless steel filter element which is built into the system.
Other patents which are pertinent in the art include the following as listed:
______________________________________ U.S. PAT. No.: INVENTOR: INVENTION: ______________________________________ 938,495 Lunstrum "Air Blue Blower" 2,846,710 Haka "Tool For Cleaning Bend Bores" 404,425 Obenchain "Boiler Cleaning Apparatus" 3,171,807 Neuman "Liquid Separating Apparatus" 4,135,946 Casey, et al "Process And Apparatus For Enchancing Growth Of Precipitables In A Chemical Solution" 3,900,397 Bell "Fuel Tank Filter" ______________________________________